On the in¯uence of carbon implantation on the structural properties of hard TiN coatings studied by glancing incidence X-ray diraction M.A. Tagliente a, * , R. Falcone b , D. Mello b , C. Esposito a , L. Tapfer a a Centro Nazionale Ricerca e Sviluppo Materiali PASTIS-CNRSM), Strada Statale 7 Appia km 712, Brindisi I-72100, Italy b Dipartimento Ingegneria dell'Innovazione, Universita' degli Studi di Lecce, via Arnesano, Lecce I-73100, Italy Received 1 August 2000; received in revised form 28 December 2000 Abstract In this work, we investigate the structural properties and, in particular, the residual stress of carbon-implanted TiN coatings by means of glancing incidence X-ray diraction and secondary ion mass spectrometry techniques. The coatingsweregrownbyion-beamphysicalvapordepositiononsteelsubstratesandsubsequentlyimplantedat100keV with carbon doses of 1 10 17 ; 3 10 17 and 7 10 17 ions=cm 2 . The carbon depth pro®les obtained by secondary ion mass spectrometry enable us to choose the more appropriate X-ray beam incidence angles in order to detect the structural variations in proximity to the implanted region. The X-ray results indicate notable variations both in the crystallinity and in the residual stress and such modi®cations depend on the carbon dose and penetration depth. In particular, in the coating implanted with a dose of 1 10 17 ions=cm 2 the initial compressive residual stress is reduced until a penetration depth of at least 400 nm. In addition, the lattice is re-crystallized in the ®rst 100 nm. The coatings implanted with doses of 3 10 17 and7 10 17 ions=cm 2 have a surface region 100 nm thick) in the tensile stress state and a peak of compressive stress well above the non-implanted value at a depth between R p and 2R p . Moreover, the eect of C implantation is to reduce the lattice parameters for all the investigated samples. Such results can be ex- plained by considering the defect distribution induced by the implantation process and the competition between the implantation amorphization and the self-annealing behavior. Ó 2001 Elsevier Science B.V. All rights reserved. PACS: 61.72.W; 81.40.J; 82.80.M; 61.10.H Keywords: Carbon ion implantation; Glancing incidence X-ray diraction; Residual stress; Titanium nitride 1. Introduction Titanium nitride TiN) thin ®lms have been largely used as protective coatings on mechanical components and cutting tools owing to their excellent mechanical and tribological properties Nuclear Instruments and Methods in Physics Research B 179 2001) 42±54 www.elsevier.nl/locate/nimb * Corresponding author. Tel.: +39-0831-507-399; fax: +39- 0831-507-379. E-mail address: taglient@cnrsm.it M.A. Tagliente). 0168-583X/01/$ - see front matter Ó 2001 Elsevier Science B.V. All rights reserved. PII:S0168-583X01)00346-9